The invention relates to an electronic component comprising:
a package having N input pins and M output pins, which are intended, respectively, to receive and supply data signals, and
an integrated circuit, which is encased in said package, and which includes N input contact pads and M output contact pads, which are connected, respectively, to the N input pins and M output pins by conducting wires, which integrated circuit includes a plurality of current paths, which are each used to connect an input contact pad to an output contact pad.
It has been observed by the current applicant that during operation of such an electronic component, certain output pins supply data signals containing parasitic components, which do not correspond to any of the data signals received by those input contact pads which are electrically connected to said output pins. The current applicant has concluded that such phenomena are caused by inductive coupling between the various conducting wires connecting the input pins to the input contact pads: due to mutual inductance effects, components representative of signals carried by wires adjoining the wire under consideration are introduced into the signal carried by said wire under consideration. These additional components are contained in the signal which will be supplied by the output pin(s) which is (are) electrically connected to the wire under consideration, and will then constitute a parasitic component in said signal. The extent of the effects of mutual inductance is wider as the frequency of the data signals is higher.
It is an object of the invention to overcome this drawback to a large extent by providing an electronic component wherein the effect of the inductive couplings between conducting wires connecting the input pins to the input contact pads are reduced substantially.
Indeed, in accordance with the invention each current path in an electronic component in accordance with the opening paragraph comprises a buffer element, exhibiting a high input impedance.
In such an electronic component, the high input impedances of said buffers cause the value of the currents flowing through the current paths upstream from the buffers, and hence the value of the currents flowing through the conducting wires connecting the input pins to the input contact pads, to be negligibly small. The extent of the mutual inductance phenomena occurring between adjacent wires, which is directly proportional to the value of the currents flowing through these wires, is thus reduced considerably, thereby precluding that a wire induces an additional component of substantial amplitude in the signal traveling through an adjacent wire. By virtue of the invention, each output pin thus supplies a signal which is representative only of signal contributions arriving at the input contact pads which are effectively electrically connected to said output pin, which signal consequently does not contain the parasitic component described hereinabove.
The buffers are advantageously composed of amplifiers, whose input impedance is naturally high, for example an assembly based on a Darlington-type structure.
In accordance with a particular embodiment of the invention, each input contact pad is connected to a buffer. This ensures that all currents flowing through the conducting wires connecting the input pins to input contact pads are negligibly small.
Although the invention can be employed in any type of electronic component comprising at least two input pins, the invention is advantageously used in multiplexers intended to receive and supply signals at very high frequencies, for example in the gigahertz range.
Thus, in a preferred embodiment of the invention, an electronic component as described hereinabove includes:
M buffer elements, each having an input and an output, the latter being connected to one of the output contact pads,
M switching stages, each comprising N switches, each switch having a first terminal and a second terminal, the first terminal being connected to one of the input contact pads, and all the second terminals being jointly connected to the input of one of the buffers, and
control means for controlling the switching stages, which are arranged in such a way that only one of the switches included in a same switching stage can be conductive at any given instant.
This structure, which is used for multiplexing, by selecting M data signals from the N signals received on the input pins in order to direct these signals towards the M output pins, only requires M buffer, instead of the N buffers, which would have been necessary in accordance with the particular embodiment described hereinabove.